How come power changeover was not seamless during power outage blip?

[charlesj]

...

Just went through doing this (flipping the breaker and running off grid for a couple days) a couple weeks back as a planned test of the system, just to make sure everything works as expected.

And, how did it go? Did you get a message? Was it recurring warning so you didn't miss it or one message blip?
Were you able to recharge batteries enough to last to next solar charge?

 

[h2ofun]

And, how did it go? Did you get a message? Was it recurring warning so you didn't miss it or one message blip?
Were you able to recharge batteries enough to last to next solar charge?

If I do not run my heating or ac, have some sun, and nothing is broken, I could be off grid I believe for a long time. But, since I cannot do this in winter, I need to send back as much solar during peak to get my 3x cost credit.

 

[wjgjr]

And, how did it go? Did you get a message? Was it recurring warning so you didn't miss it or one message blip?
Were you able to recharge batteries enough to last to next solar charge?

I got the message (I have never had the bug with notifications) - and it is just one notification, but the Tesla app also has an indication when the event is ongoing. There is a second notification when the grid connection is reestablished.

I had planned this outage for a time when I knew I would have no issue generating enough solar (cool temps, gas furnace,) so I operated mostly off-grid for 2.5 days, though I went back on-grid a few hours the second day when batteries were near full, just to not lose the solar. (I picked the time as well because of how the annual reconciliation works with my utility, and I would have preferred to directly instruct the batteries not to re-charge for a day, but direct control does not exist and normally being on backup-only, the other modes haven't done any learning.)

 

[charlesj]

If I do not run my heating or ac, have some sun, and nothing is broken, I could be off grid I believe for a long time. But, since I cannot do this in winter, I need to send back as much solar during peak to get my 3x cost credit.

Just tell the power company not to have any outages in the winter, and that is an order to them.

 

[Freakyguy666]

Seamless means no blip in the context. You can interpret it any way you want but It has been commonly used to describe the difference between line-interactive and online UPS's for years before home battery systems or Tesla existed. You are just adding confusion by bringing up battery SOC. As I and others have explained it's about whether PW is powering your house when grid power drops regardless of the reason why PW is powering your house or not at the time.

The blips are short and whether it really matters is completely customer dependent. For those that want completely seamless transition and money is no object then they should look at home scale microgrids (e.g. YouSolar) that is always powering their house. Such systems provide seamless transition just like online UPS for your whole house and there is never any frequency shifting to the house loads and generators are easily supported.

Incorrect.

“Blips” are not seamless in the common definition of the word.

Also, the SOC does matter wrt whether the “blip” is observable or not. To wit, if the soc were at 60% and PV producing sufficient power to meet demand from home when the outage occurs, the PV would continue to produce without a reset (aka “blip”). So you’re incorrect on that point as well.

 

[holeydonut]

This blog post about the TEG1 says the backup relay flip (to prevent ESS energy goes up to the PoCo) takes 200ms to 750ms. It makes sense that during these milliseconds, the PW's will not be discharging to the home either to prevent any overload condition.

Does the Tesla Powerwall 2 produce RFI (Radio Frequency Interference)?

Follow-up article: There is a follow-up article to this one describing how I mitigated what interference was being produced by the Powerwa...

ka7oei.blogspot.com

My experience with the TEG2 is the cut over to backup only seems to happen when the grid frequency dips or the power straight up goes out. These cutovers are enough for all LED lights to turn off/on, but not so long as to reset any electronics. SoC or state of my home didn't seem to matter for me. I had almost full batteries and running 100% off my own ESS+PV and all my lights still went out for a brief moment.

So that's like... 500 ms? (highly scientific assessment using my observation)

Tesla advertises "seamless" cutover for both the TEG1 and TEG2. I guess it's up for interpretation what is "seamless".

 

[jjrandorin]

There seems to be a disagreement on the definition of "seamless".... likely at least partially because, in this specific section of TMC ( tesla energy) in general, we have a lot of very technical minded people (lots of scientists / engineers / doctors etc in this section).

Before everyone gets their labcoats in a bunch ( ) maybe we should remove the word "seamless" and insert something like "able to be noticed by the average person"?

 

[jjrandorin]

Do you have Gateway 1 or 2 generation? We got Gateway 1 perhaps as left over contractors equipment installed last year when Gateway 2 was readily available to others.
Had 7 grid outages many were not seamless even when home running on Powerwalls after sunset. Swell Energy contractors swapped circuit breakers in Essential Circuit Panel, next grid shutdown still not seamless.
Any thoughts on requesting upgrade to gen 2?
James

Hi Dr. James,

I dont think the difference in gateway 1 or 2 would change whether you notice the grid outages or not (swapping from the word seamless, lol). Whether you notice them or not depends on a few different factors as I mentioned. State of charge of the powerwall(s), home load, amount of PV being produced at the time...

Whether you will notice the swap over or not depends on a few different factors which I sort of described up thread a bit, but that was not an all inclusive type statement in my post attempting to explain it (I am not capable of giving an all inclusive statement on this as I dont know all the parameters).

I do know, however, that the things I listed above can impact it (powerwall state of charge / powerwall state, PV production, how much electricity your home is using at the time of the outage (home load).

I dont know when you got installed, but gateway 2 was just becoming available in the middle of last year sometime and does not seem to have been "readily" available till later in the year. I dont think speed of swap over is one of the advantages of the new gateway.

 

[cali8484]

Incorrect.

“Blips” are not seamless in the common definition of the word.

Also, the SOC does matter wrt whether the “blip” is observable or not. To wit, if the soc were at 60% and PV producing sufficient power to meet demand from home when the outage occurs, the PV would continue to produce without a reset (aka “blip”). So you’re incorrect on that point as well.

That's just wrong. Blips during transfer from grid don't happen because there is not enough SOC or PV. PW requires about 55ms of transfer time when grid goes out (see p. 8 in http://azmag.gov/Portals/0/Document...y_Documentation.pdf?ver=2018-02-22-161139-873).

 

[Electrph]

There seems to be a disagreement on the definition of "seamless".... likely at least partially because, in this specific section of TMC ( tesla energy) in general, we have a lot of very technical minded people (lots of scientists / engineers / doctors etc in this section).

Before everyone gets their labcoats in a bunch ( ) maybe we should remove the word "seamless" and insert something like "able to be noticed by the average person"?

hey hey some of us resemble that remark !

 

[Freakyguy666]

That's just wrong. Blips during transfer from grid don't happen because there is not enough SOC or PV. PW requires about 55ms of transfer time when grid goes out (see p. 8 in http://azmag.gov/Portals/0/Documents/MagContent/Tesla_Powerwall 2_AC_Utility_Documentation.pdf?ver=2018-02-22-161139-873).

Your comprehension of my statement is incorrect.

I’ll try to make it easier to comprehend: if house were being fed by PV while PW SOC were relatively low (60-70%) when an outage occurs, the blip would be much less observable because the PV would not have to be reset.

Conversely, if the PW SOC were 98% in the above scenario, the “blip” would become “more observable” because the PV would be reset by PW.

 

[Vines]

Once more, you WANT your UPS to be frequency sensitive! Your computer may NOT be tolerant of overfrequency, so it is better that the UPS takes over at 63 Hz.

Ok I can see that argument as well. For others its probably just an annoyance.

Certainly newer inverters with partial curtailment firmware are better for the end user for exactly this reason, and in those systems the Powerwall only needs to frequency shift to 62-63 hz max

 

[jedmo]

We just experienced a power outage, house was running completely on solar, powerwalls were at 100%. Everything went out for about 5 seconds, then came back on, so not seamless.

 

[cali8484]

Your comprehension of my statement is incorrect.

I’ll try to make it easier to comprehend: if house were being fed by PV while PW SOC were relatively low (60-70%) when an outage occurs, the blip would be much less observable because the PV would not have to be reset.

Conversely, if the PW SOC were 98% in the above scenario, the “blip” would become “more observable” because the PV would be reset by PW.

Now you want redefine blip? We are talking about blip in the context of the OP's report of observing screen glitches and getting Ting alerts when grid dropped which will still happen even if PV doesn't reset.

 

[jjrandorin]

We just experienced a power outage, house was running completely on solar, powerwalls were at 100%. Everything went out for about 5 seconds, then came back on, so not seamless.

Powerwalls at 100% = PV has no place to go when the power outage happened, and needed to switch over. 5 seconds is a pretty long time for it to swap over, but "being able to notice it" if your powerwalls are full and PV is powering the home is 100% the normal operation. How much you will notice depends on whats actually backed up.

 

[jjrandorin]

(moderator note)

@cali8484 and @Freakyguy666, please keep discussion of "seamless" or not respectful between the two of you. I dont want to have to start moving posts out of this thread, so am asking politely for restraint.

 

[jedmo]

Powerwalls at 100% = PV has no place to go when the power outage happened, and needed to switch over. 5 seconds is a pretty long time for it to swap over, but "being able to notice it" if your powerwalls are full and PV is powering the home is 100% the normal operation. How much you will notice depends on whats actually backed up.

It probably felt longer than it was, as I was in shock that it wasn't seamless. Lights went out and tv clicked off, the oven clocked blinked on and off similar to if the power went out and came back on. We do have the whole house backed up. I figured the solar would kick off since the powerwalls were at 100%, but I didn't think I would notice or see anything actually power off. I remember when the Tesla installer demoed the Powerwalls after the install, it was seamless during his demo.

 

[jjrandorin]

It probably felt longer than it was, as I was in shock that it wasn't seamless. Lights went out and tv clicked off, the oven clocked blinked on and off similar to if the power went out and came back on. We do have the whole house backed up. I figured the solar would kick off since the powerwalls were at 100%, but I didn't think I would notice or see anything actually power off. I remember when the Tesla installer demoed the Powerwalls after the install, it was seamless during his demo.

Thats because powerwalls are not delivered at 100% charge, so in that situation, the PV has someplace to go, and happily continues powering the home and filling the powerwalls.

 

[wjgjr]

It probably felt longer than it was, as I was in shock that it wasn't seamless. Lights went out and tv clicked off, the oven clocked blinked on and off similar to if the power went out and came back on. We do have the whole house backed up. I figured the solar would kick off since the powerwalls were at 100%, but I didn't think I would notice or see anything actually power off. I remember when the Tesla installer demoed the Powerwalls after the install, it was seamless during his demo.

This surprises me based on our experience. We operate in backup-only mode, meaning PWs are never powering the house, so we are subject to the longer delays for the PWs to take over. Even with that, we have yet to have our oven or microwave clock go out during an outage, and we used to not even set the microwave because it would go out if you looked at it wrong. It was mentioned earlier in the thread that the nature of the outage can affect when the system cuts over to PWs, so it is possible if it was not a clean power loss that might explain it, and why it was different from when your installer likely flipped a breaker (a clean power cut.)

 

[Freakyguy666]

Now you want redefine blip? We are talking about blip in the context of the OP's report of observing screen glitches and getting Ting alerts when grid dropped which will still happen even if PV doesn't reset.

Incorrect.

You simply did not comprehend my previous response and now you want to define “blip” to exclude that which I originally referenced.

The more relevant question, again, is what is the soc level where the PV will NOT be reset? Anyone? Bueller?